I don't think this version we have will ever be able to tether but thats just my opinion.. maybe in near future? The phone isn't even fast enough (network wise) to even surf on a laptop in my opinion.. I tether with my blackberry thats pretty quick at like 1mb or 2mb someitmes...
Using the cellphone as a wireless "modem/router" to connect another computer to the internet. They might make that available... maybe. I doubt it though.
There are some DSL customers on the "boundaries" running max 384k who might just cancel their DSL if they could get a reliable 100k via tethering with an unlimted data package on their $600 / $60 a month phone.
Never know though. They do it with other phones they sell... for a price.